The present invention relates to absorbent articles for retaining body fluids such as urine, menses, or faecal material, and in particular to their ability to acquire and retain aqueous based materials. The invention further relates to disposable absorbent articles such as baby diapers or training pants, adult incontinence products, and feminine hygiene products.
Disposable absorbent articles are well know from the art for receiving and retaining bodily discharges, such as urine, menstrual fluids, or faecal materials. Thereby, two basic mechanisms are relied on. First, the containment of such discharges is generally achieved by a gasketing functionality, such as through impermeable materials or construction of sealings between the article andxe2x80x94in most casesxe2x80x94the skin of the wearer. The other key mechanism is to retain the discharges within the absorbent article, generally achieved by using an absorbent structure to pick up the discharges. In most cases, the absorption mechanism is directed towards handling of the aqueous components of the discharges.
One of the key performance criteria against which an absorbent article has to deliver is the acquisition speed. Obviously, a fast liquid acquisition warrants a short time span between exudation and storage of the exudate. Another key performance criterion is the dryness of the user facing surface of the absorbent article. To match the wearing comfort of regular underwear, a dry touch of the user facing surface is desired.
Thereby, one of the key transport and storage phenomena is related to the capillary effects of the structures, whereby one property of the materials used for constructing such structures is of critical importance is the porosity of the structure. The smaller the capillaries are the higher is the capillary suction.
Simultaneously, it has been a trend in recent absorbent articles to provide the capability to handle high viscosity liquids such as faeces. Because of the high viscosity of such liquids, it is desirable that the respective acquisition structures provide large open pores in order to readily accept such liquids. For example such structures are described in WO 95/05139 (Roe), in PCT/US97/20840 (Bast et al.), and in PCT/US98/24389 (Roe et al.).
Inevitably, such large open pores limit the liquid handling capabilities of such open structures by reducing their capillary suction. Therefore, it has been suggested in the prior art to provide an absorbent article which has good liquid acquisition performance in the front region and has good high viscosity liquid handling capabilities in its back region. Such an absorbent article is described for example in PCT/US97/20841 (Bast et al.).
Therefore, it is an object of the present invention to provide an absorbent article which overcomes the problems posed by the prior art absorbent articles.
It is a particular object of the present invention to provide an absorbent article which has good low viscosity liquid handling performance as well as good high viscosity liquid handling performance in its front region.
It is a further object of the present invention provide an absorbent article which has a high in liquid acquisition speed and low liquid rewet through the topsheet.
It is a further object of the present invention provide an absorbent article which comprises a liquid handling structure having large open pores which effectively handles low viscosity liquids and high viscosity liquids such as faeces.
The present invention provides a disposable absorbent article having a transverse centerline, a first region, and a second region, the first region being positioned forward of the transverse centerline, the first region coming into contact with the front waist of the wearer during use, the second region being positioned backward of the transverse centerline, and the second region coming into contact with the back waist of the wearer during use. The absorbent article of the present invention comprises a liquid pervious structured carrier, a liquid impervious backsheet at least partially peripherally joined to the structured carrier, a liquid storage structure positioned intermediate the topsheet and the backsheet, and a liquid handling structure positioned intermediate the topsheet and the liquid storage structure. A portion of the liquid handling structure is positioned in the first region and a portion of the liquid handling structure is positioned in the second region. The absorbent article of the present invention is characterised in that the absorbent article has a topsheet wetness value of less than 120 milligrams according to the Topsheet-Finished-Product-Wetness Test Method disclosed herein and the disposable absorbent article has a front region Storage Under Pressure under pressure of at least 800 grams per square meter according to the Storage Under Pressure Test disclosed herein.
The present invention further provides a disposable absorbent article wherein the disposable absorbent article has a front region total product acquisition performance of more than 3.75 ml/s in the first gush and of more than 0.5 ml/s in the fourth gush.
The present invention further provides a disposable absorbent article wherein the disposable absorbent article has a front region Skin Hydration value of less 120 mg according to the Collagen Rewet Test Method defined herein.
The present invention further provides a disposable absorbent article wherein the disposable absorbent article has a front region immobilisation under compressed inversion of at least 70% according to Immobilisation Under Compressed Inversion Test disclosed herein.
The present invention further provides a disposable absorbent article wherein the disposable absorbent article has a front region retention under compressed inversion of least 7.5 grams according to the Retention Under Compressed Inversion Test disclosed herein.
The present invention further provides a disposable absorbent article wherein the disposable absorbent article has a back region Storage Under Pressure of at least 0.5 grams per square metre according to the Storage Under Pressure Test disclosed herein.
The present invention further provides a disposable absorbent article wherein the disposable absorbent article has a back region immobilisation under compressed inversion of at least 70% according to the Immobilisation Under Compressed Inversion Test disclosed herein.
The present invention further provides a disposable absorbent article wherein the disposable absorbent article has a back region retention under compressed inversion of at least 7.5 g according to the Retention Under Compressed Inversion Test disclosed herein.
The present invention further provides a disposable absorbent article wherein the structured carrier comprises a plurality of apertures having a size of at least 0.2 mm2.
The present invention further provides a disposable absorbent wherein the structured carrier has a open area of more than 12%.
The present invention further provides a disposable absorbent article wherein the liquid handling structure has a compression resistance of at least 70% under an applied pressure of 1 Newton per square centimeter.
The present invention further provides a disposable absorbent article wherein the liquid handling structure has a resiliency of at least 50% after 30 seconds under an applied pressure of 1 Newton per square centimetre.
The present invention further provides a disposable absorbent article wherein the liquid handling structure has a basis weight to uncompressed calliper ratio of less than 100 grams per square meter per millimeter.
The present invention further provide a disposable absorbent article wherein the liquid handling structure comprises a backing and a sheet of fibres, the sheet of fibres having anchor portions in the backing at spaced bonding locations and having arcuate portions of the sheet projecting from the backing between bonding locations.